<template>
  <div>
    <h2>我是child组件</h2>
    <button @click="handle">累加app中的count</button>
    <button @click="off">解绑</button>
  </div>
</template>

<script>
export default {
  name: "Child",
    methods:{
      handle(){
        this.$emit("changeCount",2)
      },
      // 解绑
      off(){
        this.$off(["changeCount"])
      }
    }
};
</script>

<style>

</style>
